The subject matter herein relates generally to electrical connector assemblies, and more particularly, to circuit boards for electrical connector assemblies.
To meet digital multi-media demands, higher data throughput is often desired for current digital communications equipment. Electrical connectors that interconnect circuit boards must therefore handle ever increasing signal speeds at ever increasing signal densities. One application environment that uses such electrical connectors is in high speed, differential electrical connectors, such as those common in the telecommunications or computing environments. In a traditional approach, two circuit boards are interconnected with one another in a backplane and a daughter board configuration. However, at the footprints of the circuit boards where the electrical connectors connect thereto, it may be difficult to improve density while maintaining electrical performance and/or reasonable manufacturing cost. For example, in known circuit boards, vias within the circuit boards are plated, creating plated through-holes (PTHs) that are electrically connected to corresponding traces in the circuit board. A certain aspect ratio of the via diameter to the via length must be maintained for effective plating. Contacts extending from the electrical connectors are connected to the PTHs, and thus the traces, using eye-of-the-needle contacts.
Known electrical connectors having PTHs are not without disadvantages. For instance, the PTHs create electrical problems, such as low impedance and high cross-talk through the circuit board. One method of improving such footprints is to counterbore a portion(s) of the PTHs to remove the plating to an area just in the vicinity of the corresponding trace in the circuit board. However, the same problems still remain in the short length of the non-bored PTHs that remain for interfacing the contacts with the traces. Such region, though short, still has low impedance, which becomes increasingly problematic at higher transmission speeds.
To achieve higher system densities and speed, further improvement of circuit board footprints and connections to the circuit boards must be made over known approaches. There is a need for an electrical connector that enables improvement of the density and/or electrical performance of circuit board footprints to achieve higher system densities and/or higher system speeds.